Synthesis of enantioenriched γ-quaternary cycloheptenones using a combined allylic alkylation/Stork–Danheiser approach: preparation of mono-, bi-, and tricyclic systems
作者:Nathan B. Bennett、Allen Y. Hong、Andrew M. Harned、Brian M. Stoltz
DOI:10.1039/c1ob06189e
日期:——
A general method for the synthesis of β-substituted and unsubstituted cycloheptenones bearing enantioenriched all-carbon γ-quaternary stereocenters is reported. Hydride or organometallic addition to a seven-membered ring vinylogous ester followed by finely tuned quenching parameters achieves elimination to the corresponding cycloheptenone. The resulting enones are elaborated to bi- and tricyclic compounds with potential for the preparation of non-natural analogs and whose structures are embedded in a number of cycloheptanoid natural products.
Development of a catalytic enantioselective synthesis of the guanacastepene and heptemerone tricyclic core
作者:Andrew M. Harned、Brian M. Stoltz
DOI:10.1016/j.tet.2019.02.053
日期:2019.6
approaches to these compounds have been reported, but to date the application of enantioselective catalysis to this problem has not been realized. Herein we report an enantioselective synthesis of an advanced intermediate corresponding to the tricyclic core common to the guanacastepenes and heptemerones. Highlights of this work include sequential Pd-catalyzed decarboxylative allylicalkylation reactions to
Development of (Trimethylsilyl)ethyl Ester Protected Enolates and Applications in Palladium-Catalyzed Enantioselective Allylic Alkylation: Intermolecular Cross-Coupling of Functionalized Electrophiles
作者:Corey M. Reeves、Douglas C. Behenna、Brian M. Stoltz
DOI:10.1021/ol500355z
日期:2014.5.2
compounds in palladium-catalyzedasymmetricallylicalkylation is explored, yielding a variety of α-quaternary six- and seven-membered ketones and lactams. Independent coupling partner synthesis engenders enhanced allyl substrate scope relative to traditional β-ketoester substrates; highly functionalized α-quaternary ketones generated by the union of (trimethylsilyl)ethyl β-ketoesters and sensitive
Progress towards the total synthesis of hamigerans C and D: a direct approach to an elaborated 6-7-5 carbocyclic core
作者:Douglas Charles Duquette、Thomas Jensen、Brian Mark Stoltz
DOI:10.1038/ja.2017.96
日期:2018.2
The hamigeran family of natural products has been the target of numerous syntheticefforts because of its biological activity and interesting structural properties. Herein, we disclose ourefforts toward the synthesis of hamigerans C and D, unique among the initially isolated members because of their 6-7-5 carbocyclic core. Our approach directly targets this tricyclic motif by sequential Negishi and
Palladium-catalyzed asymmetric alkylation in the synthesis of cyclopentanoid and cycloheptanoid core structures bearing all-carbon quaternary stereocenters
作者:Allen Y. Hong、Nathan B. Bennett、Michael R. Krout、Thomas Jensen、Andrew M. Harned、Brian M. Stoltz
DOI:10.1016/j.tet.2011.10.031
日期:2011.12
reagents enabled divergent access to γ-quaternary acylcyclopentenes through a ringcontraction pathway or γ-quaternary cycloheptenones through a carbonyl transposition pathway. Synthetic applications of these compounds were explored through the preparation of mono-, bi-, and tricyclic derivatives that can serve as valuable intermediates for the total synthesis of complex natural products. This work complements